The challenge

The importance of accurate, secure and durable identification of biological or medical samples cannot be under-estimated.

Central Labo, a French company specialising in the manufacture of plastic medical devices found themselves faced with the challenge of ensuring the individual tracability of biological samples stored in particular containers. Each container holds 48 separate wells destined to hold samples of blood or serum.

Prior to this each container of samples was simply identified as a whole using a bar code. In the event of even one problem sample, the entire container had to be rejected. In order to make it possible to identify individual wells Central Labo realised they needed a very special marking process, capable of dealing with the tiny surfaces of the individual wells.

The tiny size of each well meant an unprecedented requirement for DPM (Direct Part Marking) and the need for complete tracability demanded an automated marking process capable of integrating the necessary data handling which was also tailored to meet the specific needs and technical requirements of Central Labo. The solution needed to mark two different codes with a result that would be both machine-legible and visible to the human eye even after long periods of time.

Technical constraints were significant in that the solution would have to be a completely automated process complying with Class 10000 clean-room conditions, maintain zero risk of error and ensure any non-conforming pieces are rejected during the process all while meeting production requirements of one piece per minute.

An innovative and tailor-made solution

After having looked at several possible partners, Central Labo chose Technifor. Technifor was the only company proposing to meet the specific needs of Central Labo. Dominque Lambert, head of research and development for Central Labo said that Technifor’s experience in advanced laser marking plus their ability to provide the necessary vision system through their partnership with Cognex were two of the main factors that led to him choosing Technifor fo2 the application solution. Data Matrix technology was the best solution in terms of the sheer amount of information that needed to be securely marked onto such a small surface.

Technifor’s personalised machine department were capable not only of offering the necessary laser marking process but also the means to both verify and read all the codes involved using Cognex vision whose In-Sight® system completed the application.

The first step in the process involves the container being manually loaded holding 48 wells and identified using bar codes. Each individual unit is then individually marked using a laser. Each well is marked with the container code as well as it’s own unique identification code in human readable text. In addition a Data Matrix machine readable code is added containing the same information. At this point each of the codes has to be inspected and verified to ensure that they can be decoded.

Cognex In-Sight: Position verification and decoding

The Cognex In-Sight vision camera is mounted in such a way so as to be able to individually read each of the codes on each sample. The use of Cognex PatFind® technology greatly aids the inspection and verification process. The positioning of the vials is verified by the vision system and the camera relays the information via a mirror. Codes are decoded during an automated process which compares the relayed information with that which it was expecting. In case of error the process is momentarily interrupted and the bad piece is rejected.

The entire process takes just one minute per set of 48 wells which means the company benefits from increased efficiency as well as 100% reliability.

Central Labo is one of Europe’s largest laboratories processing hundreds of biological samples each day. While speed is of the essence, the nature of the samples requires complete accuracy and reliability in terms of identification and traceability.

Complete identification and tracability is now an industry pre-requisite for the medical and pharmaceutical equipment sectors.

The paired ability of Technifor and Cognex to provide not only a precise laser marking system but also an advanced vision system to read the codes gave them the added value needed to be chosen by Central Labo. Technifor had the advantage of being one of the first movers in using the Data Matrix marking that has become a standard in the industry.

This kind of reduction of error and false rejects is of great benefit to productivity leading to increased level of confidence in the laboratory’s handling of important medical samples.

Central Labo have a new work tool based on their unique needs. The solution provided by Technifor and Cognex is one based on standard components such as the In-Sight vision system which are used in a made-to-measure solution allowing Central Labo to solve a complex identification application. Efficiency, security and tracability are all ensured without compromising safety standards.